California earthquakes

M2.8 earthquake 26 km WNW of Three Rocks, California

A magnitude 2.8 earthquake struck 26 km WNW of Three Rocks, California on Fri, Apr 20, 1979, 1:23 AM PST (09:23 UTC), 3 km (2 mi) below the surface.

A larger quake followed: M3.4 23 km ENE of Soledad, California. This one was a foreshock.

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Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude
2.8 (md), micro
Local time
UTC
1979-04-20 09:23:36 UTC
Depth
2.8 km (1.7 mi), shallow
Epicenter
36.621° N, 120.654° W
Tsunami flag
No
Status
Reviewed by a seismologist

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty
About 1.0 km horizontally, 1.1 km in depth
Magnitude uncertainty
±0.17
Depth from
From location
Station coverage gap
272°, poorly surrounded by stations
Stations used
29

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Nearby

Within 100 km, magnitude 1.5 and up: 140 in the 60 days after this one and 52 in the 30 days before it.

After

The first 60 of 140.

Before

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc1045482 (also filed as ci3314839). Read Tue, Sep 29, 2026, 2:47 PM UTC.